Volume 6, Issue 6 (June 2009)
Guide on Measuring Uniformity of Furnace Exposure on Specimens Representing Test Samples Used to Determine Fire Resistance Ratings
ASTM E5.11 Subcommittee on fire resistance is responsible for five fire test standards that rely upon furnaces to provide the heat exposure to test samples. These test samples range from floor-ceiling samples having a minimum area of 16.7 m2 to firestop systems that may include a single relatively small penetrating item. All these test standards include a precision and bias clause but none of the standards include a means for documenting the exposure or fire insult conditions imposed by the furnace onto the sample. This paper describes the activity underway within ISO TC92/SC2 to publish a procedure to measure the uniformity of furnace exposure imposed upon test samples. This procedure measures the temperature on a specimen replicating a test sample used to determine fire resistance ratings, the oxygen content in the furnace chamber, and the velocity across the specimen. The ISO method introduces the term “effective area of furnace opening” to identify the area within the furnace opening where the test specimen is not significantly influenced by furnace boundary conditions. The method is applicable to all ASTM fire test standards that use furnaces such as ASTM E119 as well as similar ISO and NFPA standards.